CN1273577C - Use of copolymers containing alkylene oxide units, as an additive in detergents and cleansers - Google Patents

Abstract

The use of copolymers containing alkylene oxide units and (mole%): (a) acrylic acid and/or one of its a water soluble (50-93), (b) methacrylic acid and/or one of its a water soluble salts (5-30), and (c) at least one nonionic monomer (2-20), statistically or block polymerized as washing and cleaning material additives is new. The use of copolymers containing alkylene oxide units and (mole%): (a) acrylic acid and/or one of its water soluble salts (50-93); (b) methacrylic acid and/or one of its a water soluble salts (5-30); and (c) at least one nonionic monomer (2-20) of formula (I). R1 = H or Me, R2 = chemical bond or optionally branched 1-6C alkylene, R3 = optionally branched 2-4C alkylene, R4 = optionally branched 1-6C alkyl, n = 3-50, statistically or block polymerized as washing and cleaning material additives. An Independent claim is also included for a washing and cleaning material containing the copolymer as a coating inhibiting additive.

Description

Use of copolymers containing alkylene oxide units as additives in detergents and cleaning agents

The present invention relates to the use of copolymers containing alkylene oxide units as additives in detergents and cleaning agents, which copolymers comprise, in random or block copolymerized form:

(a) 50-93 mol% acrylic acid and/or water-soluble salts of acrylic acid,

(b) 5-30 mol% methacrylic acid and/or water-soluble salts of methacrylic acid, and

(c) 2-20 mol% of at least one nonionic monomer of formula I:

where the variables have the following meanings:

R ¹ is hydrogen or methyl;

R ² is a chemical bond or unbranched or branched C ₁ -C ₆ alkylene;

R ³ is the same or different unbranched or branched C ₂ -C ₄ alkylene;

R ⁴ is unbranched or branched C ₁ -C ₆ alkyl;

n is 3-50.

The present invention further relates to washing and cleaning agents comprising these copolymers as deposit inhibiting additives.

In the case of machine dishwashing, the dishes should be left clean without residue and should have a flawlessly shiny surface, for which it is usually necessary to use detergents, rinse aids and regeneration salts for water softening.

Commercially available "2-in-1" dishwashing detergents contain, in addition to detergent for removing soil from dishes, a clear-rinse surfactant integrated therein, which ensures during clear-rinse and dry operations The unfolded water runs off over the cutlery, thus preventing dirt and water marks. The use of these products no longer requires the injection of rinse aid.

Modern machine dishwashing detergents, "3 in 1" detergents, intend to combine the three functions of detergent, rinse aid and water softening in a single detergent formula, which means that the water hardness of 1-3 is The injection of salt also becomes superfluous to the consumer. Sodium tripolyphosphate is often added to these detergents in order to bind the hardness-producing calcium and magnesium ions. However, this in turn leads to deposits of calcium and magnesium phosphate on the tableware.

EP-A-324 568 describes water-soluble copolymers for detergents and cleaners by mixing acrylic acid, methacrylic acid and polyethylene glycol with long-chain alkoxy and/or long-chain in the presence of isopropanol Alcohol-blocked alkoxypolyethylene glycol methacrylate is polymerized. The alkoxypolyethylene glycol methacrylate fraction of these copolymers is <1 mol%.

According to JP-A-1991/185184, it is possible to use polyethylene glycol based on at least one monomer selected from maleic acid, acrylic acid and methacrylic acid and optionally methoxylated or ethoxylated polyethylene glycol as a further monomer. Copolymers of alcohol (meth)acrylates for desizing, cleaning, bleaching and dyeing of natural and synthetic fibers with an average molecular weight _Mw of 1000-10000. Specifically disclosed are copolymers of acrylic acid and methoxypolyethylene glycol methacrylate.

JP-A-2000/24691 describes copolymers of unsaturated carboxylic acids and monomers containing _{polyoxyalkylene} units with an average molecular weight Especially based on silicates. Also specifically disclosed are only copolymers of acrylic acid and methoxypolyethylene glycol methacrylate.

It is an object of the present invention to overcome the above-mentioned problems and to provide additives which can be used particularly advantageously in multipurpose cleaners and which at the same time have especially a deposit-inhibiting effect.

We have found that this object is achieved by the use as additives in detergents and cleaners of copolymers containing alkylene oxide units, comprising in random or block copolymerized form:

(a) 50-93 mol% acrylic acid and/or water-soluble salts of acrylic acid,

(b) 5-30 mol% methacrylic acid and/or water-soluble salts of methacrylic acid, and

(c) 2-20 mol% of at least one nonionic monomer of formula I:

where the variables have the following meanings:

R ¹ is hydrogen or methyl;

R ² is a chemical bond or unbranched or branched C ₁ -C ₆ alkylene;

R ³ is the same or different unbranched or branched C ₂ -C ₄ alkylene;

R ⁴ is unbranched or branched C ₁ -C ₆ alkyl;

n is 3-50.

We have also found detergents and cleaners comprising copolymers comprising oxyalkylene units as deposit inhibiting additives.

Copolymers containing oxyalkylene units comprise as copolymerization components (a) and (b) acrylic acid or methacrylic acid and/or water-soluble salts of these acids, especially alkali metal salts such as potassium salts and mainly sodium salts, and ammonium salt.

The proportion of acrylic acid (a) in the copolymer to be used according to the invention is 50-93 mol%, preferably 65-85 mol%, particularly preferably 65-75 mol%.

Methacrylic acid (b) is present in the copolymers to be used according to the invention in an amount of 5-30 mol%, preferably 10-25 mol%, especially 15-25 mol%.

The copolymer comprises as component (c) a nonionic monomer of formula I:

where the variables have the following meanings:

^R is hydrogen or preferably methyl;

R ² is unbranched or branched C ₁ -C ₆ alkylene or preferably a chemical bond;

R ³ is identical or different unbranched or branched C ₂ -C ₄ alkylene, mainly C ₂ -C ₃ alkylene, especially ethylene;

R ⁴ is unbranched or branched C ₁ -C ₆ alkyl, preferably C ₁ -C ₂ alkyl;

n is 3-50, preferably 5-40, particularly preferably 10-30.

Particularly suitable examples of monomer II that may be mentioned are: methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, methoxypolytetramethylene glycol (methyl ) acrylate, methoxypoly(propylene oxide/ethylene oxide copolymer) (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, ethoxypolypropylene glycol (meth)acrylate, Ethoxylated polytetramethylene glycol (meth)acrylate and ethoxylated poly(propylene oxide/ethylene oxide copolymer) (meth)acrylate, among which methoxypolyethylene glycol (meth)acrylate and Methoxypolypropylene glycol (meth)acrylate, particularly preferably methoxypolyethylene glycol methacrylate.

The polyalkylene glycols here contain 3 to 50, especially 5 to 40, especially 10 to 30, alkylene oxide units.

The proportion of nonionic monomers (c) in the copolymers to be used according to the invention is 2-20 mol %, preferably 5-15 mol %, especially 5-10 mol %.

The copolymers to be used according to the invention preferably contain —SO ₃ ^{—Na +} and/or —SO ₄ ^{—Na +} as end groups.

The copolymers to be used according to the invention generally have an average molecular weight M _w of 3000-50000, preferably 10000-30000, particularly preferably 15000-25000.

The K value of the copolymer is usually 15-40, especially 20-35, especially 27-30 (according to H.Fikentscher, Cellulose-Chemie, volume 13, pages 58-64 and 71-74 (1932) in 1 weight % concentration in aqueous solution measured at 25°C).

The copolymers to be used according to the invention can be prepared by free-radical polymerization of the monomers. In this regard, any known free-radical polymerization method may be followed. Besides bulk polymerization, mention may especially be made of solution polymerization and emulsion polymerization processes, solution polymerization being preferred.

The polymerization is preferably carried out with water as solvent. However, it is also possible to carry out the polymerization in alcoholic solvents, especially C ₁ -C ₄ alcohols, such as methanol, ethanol and isopropanol, or mixtures of these solvents with water.

Suitable polymerization initiators are compounds which decompose thermally or photochemically (photoinitiators) to form free radicals.

Among heat-activatable polymerization initiators, preference is given to initiators having a decomposition temperature of 20-180°C, especially 50-90°C. Examples of suitable thermal initiators are inorganic peroxygen compounds such as peroxodisulfates (ammonium peroxodisulfate and preferably sodium peroxodisulfate), persulfates, percarbonates and hydrogen peroxide; organic peroxo compounds such as Diacetyl peroxide, di-tert-butyl peroxide, diamyl peroxide, dioctanoyl peroxide, didecanoyl peroxide, dilauroyl peroxide, dibenzoyl peroxide, di(o-tolyl peroxide) ), tert-butyl peroxysuccinyl, tert-butyl peracetate, tert-butyl permaleate, tert-butyl perisobutyrate, tert-butyl perpivalate, tert-butyl peroctoate, tert-butyl perneodecanoate , tert-butyl perbenzoate, tert-butyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, tert-butyl peroxy-2-ethylhexanoate and diisopropyl peroxydicarbamate; Azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile) and azobis(2-amidopropane) dihydrochloride.

These initiators can be used in combination with reducing compounds as initiator/regulator systems. Examples of such reducing compounds that may be mentioned are phosphorus compounds such as phosphorous acid, hypophosphite and phosphinate; sulfur compounds such as sodium bisulfite, sodium sulfite and sodium formaldehyde sulfoxylate; and hydrazine .

Examples of suitable photoinitiators are benzophenones, acetophenones, benzoin ethers, benzyl dialkyl ketones and derivatives thereof.

Preference is given to using thermal initiators, preferably inorganic peroxygen compounds, especially sodium peroxodisulfate (sodium persulfate). It is particularly advantageous to use peroxy compounds as redox initiator systems in combination with sulfur-containing reducing agents, especially sodium bisulfite. If this starter/regulator system is used, copolymers are obtained which contain —SO ₃ ^{—Na +} and/or —SO ₄ ^{—Na +} as end groups and are distinguished by a special cleaning ability and deposit-inhibiting effect.

In addition, it is also possible to use phosphorus-containing starter/regulator systems, such as hypophosphite/phosphonite.

The amount of photoinitiator and/or starter/regulator system must be adapted to the substances used in each case. For example, if peroxodisulfate/bisulfite systems are preferably used, typically 2-6% by weight, preferably 3-5% by weight, of peroxodisulfate and typically 5-30%, preferably 5-10% by weight are used The bisulphite salts are based in each case on the monomers (a), (b) and (c).

It is also possible, if desired, to use polymerization regulators. Suitable compounds are those known to the person skilled in the art, for example sulfur compounds such as mercaptoethanol, 2-ethylhexyl thioglycolate, thioglycolic acid and dodecylmercaptan. If polymerization regulators are used, they are generally used in amounts of 0.1 to 15% by weight, preferably 0.1 to 5% by weight, particularly preferably 0.1 to 2.5% by weight, based on the monomers (a), (b) and (c).

The polymerization temperature is usually 30-200°C, preferably 50-150°C, particularly preferably 80-120°C.

The polymerization can be carried out under atmospheric pressure, but is preferably carried out in a closed system under the self-pressure generated.

In the preparation of the copolymers to be used according to the invention, the monomers (a), (b) and (c) can be used directly, but it is also possible to use the reaction mixture produced during the preparation of the monomer (c). Thus, for example, instead of methoxypolyethylene glycol methacrylate, it is possible to use the monomer mixture formed during the esterification of polyethylene glycol monomethyl ether with an excess of methacrylate. Advantageously, the esterification can also be carried out in situ in the polymerization mixture by parallel mixing (1) acrylic acid, (2) a mixture of methacrylic acid and polyethylene glycol monomethyl ether and (3) a free-radical starter. If appropriate, catalysts necessary for the esterification, such as methanesulfonic acid or p-toluenesulfonic acid, can additionally be used here.

The copolymers to be used according to the invention can also be prepared by polymer-analogous reactions, for example by reaction of acrylic/methacrylic acid copolymers with polyalkylene glycol monoalkyl ethers. However, free-radical copolymerization of the monomers is preferred.

If desired for the application, the aqueous solution produced during the preparation of the copolymer containing carboxylic acid groups to be used according to the invention can be neutralized or partially neutralized by adding a base, especially sodium hydroxide solution, i.e. the pH Adjusted to 4-8, preferably 4.5-7.5.

The copolymers used according to the invention are highly suitable as additives for detergents and cleaning agents.

They can be used especially advantageously in machine dishwashing detergents. They are mainly characterized by a deposition inhibiting effect on both inorganic as well as organic deposits. In particular, deposits caused by other ingredients of the cleaning formulation, such as deposits of calcium and magnesium phosphates, calcium and magnesium silicates, and calcium and magnesium phosphonates, as well as stains from washing liquids, should be mentioned. Deposits of dirt components such as fat, protein and starch deposits. The copolymers used according to the invention thus also increase the cleaning power of the dishwashing detergents. Furthermore, even at low concentrations, they facilitate the runoff of water from dishes, which means that the amount of rinse aid surfactants in dishwashing detergents can be reduced. If copolymers containing sulfonic acid groups are used, particularly transparent glass dishes and shiny metal cutlery are obtained, especially when the dishwashing machine is operated without the use of regeneration salts to soften the water. Therefore, the copolymers containing sulfonic acid groups can be used not only in 2-in-1 detergents, but also in 3-in-1 detergents.

The copolymers used according to the invention can be used directly in the form of aqueous solutions produced during the preparation and also in dry form obtained, for example, by spray drying, fluidized spray drying, drum drying or freeze drying. The washing and cleaning agents according to the invention can be prepared accordingly in solid or liquid form, for example powders, granules, extrudates, tablets, liquids or gels.

Example

A) Preparation of copolymers containing oxyalkylene units

Example 1

In a reactor equipped with nitrogen inlet, reflux condenser and metering device, a mixture of 619 g of distilled water and 2.2 g of phosphorous acid was heated to an internal temperature of 100° C. under introduction of nitrogen and stirring. Then within 5 hours, a mixture of (1) 123.3g acrylic acid and 368.5g distilled water, (2) a mixture of 18.4g sodium peroxodisulfate and 164.6g distilled water, (3) 72.0g water, 49.1g methacrylic acid was added continuously in parallel and 166.9 g of a mixture of methoxypolyethylene glycol methacrylate (M _w =1100) and (4) 46 g of a 40% strength by weight aqueous solution of sodium bisulfite. After post-stirring at 100° C. for 2 hours, the reaction mixture was cooled to room temperature and the pH was adjusted to 7.2 by adding 190 g of 50% strength by weight sodium hydroxide solution.

This gave a slightly yellow, transparent copolymer solution with a solids content of 25.7% by weight and a K value of 27.2 (1% strength by weight in water, 25° C.).

Example 2

In the reactor in Example 1, a mixture of 221.6 g of distilled water and 1.1 g of phosphorous acid was heated to an internal temperature of 100° C. with nitrogen introduction and stirring. Then within 5 hours, a mixture of (1) 38.6g acrylic acid and 231.0g distilled water, (2) 29.6g toluene, 27.7g methacrylic acid and 116.6g methoxy polyethylene glycol methacrylate (M _w = 1100) and (3) 68.6 g of a 40% strength by weight aqueous solution of sodium bisulfite. Parallel to this, a mixture of 9.1 g of sodium peroxodisulfate and 82.3 g of distilled water was added within 5.25 hours. In parallel to these feeds, a mixture of water and toluene was distilled off continuously and water was returned to the reaction (azeotropic removal of toluene).

After post-stirring at 100° C. for 1 hour, the reaction mixture was cooled to room temperature and the pH was adjusted to 7.2 by adding 85 g of 50% strength by weight sodium hydroxide solution.

A clear polymer solution with a solids content of 28.8% by weight and a K value of 28.9 (1% strength by weight in water, 25° C.) was obtained.

B) Use of copolymers containing oxyalkylene units in dishwashing detergents

To test their deposition inhibiting effect, the resulting copolymers were used with dishwashing detergent formulations having the following composition:

50% by weight sodium tripolyphosphate (Na ₃ P ₃ O ₁₀ 6H ₂ O)

27% by weight sodium carbonate

3% by weight sodium disilicate (xNa ₂ O·ySiO ₂ ; x/y=2.65; 80% concentration)

6% by weight sodium percarbonate (Na ₂ CO ₃ 1.5H ₂ O ₂ )

2% by weight Tetraacetylenediamine (TAED)

2% by weight Low-foaming nonionic surfactant based on fatty alcohol alkoxylates

3% by weight NaCl

5% by weight sodium sulfate

2% by weight polyacrylic acid sodium salt ( _Mw 8000)

The test was carried out under the following washing conditions without the addition of inert soil (Ballastschmutz), without the use of rinse aids and regeneration salts:

Washing conditions:

Dishwasher: Miele G 686 SC

Washing programs: 2 normal washing programs at 55°C (no prewash)

Cutlery: knife (WMF Tafelmesser Berlin, Monoblock) and barrel glass

Glass beaker (Matador, Ruhr Kristall)

Dishwashing detergent: 21g

Copolymer: 4.2g

Transparent rinse temperature: 65°C

Water hardness: 25° German hardness

The dishes were rated 18 hours after washing by visual evaluation in a darkened light box with a halogen point light source and a pinhole aperture using a scale of 10 (very good) to 1 (very poor). The highest rating of 10 here corresponds to a surface free of deposits and droplets, from a rating of <5 deposits and droplets are visible under normal room lighting and are therefore rated as troublesome.

The test results obtained are listed in the table below.

surface Copolymer Example evaluation (rating) knife Glass 1 8.0 7.7 2 6.2 7.5 4.0 4.0

Claims (7)

1. as the purposes of additive, this multipolymer comprises with random or block copolymerization form the multipolymer that contains oxyalkylene units in washing composition and sanitising agent:

(a) 50-93mol% vinylformic acid and/or acrylic acid water-soluble salt,

(b) water-soluble salt of 5-30mol% methacrylic acid and/or methacrylic acid and

(c) non-ionic monomer of at least a formula I of 2-20mol%:

Wherein each variable has following meanings:

R ¹Be hydrogen or methyl;

R ²Be chemical bond or not branching or branching C ₁-C ₆Alkylidene group;

R ³Be identical or different not branching or branching C ₂-C ₄Alkylidene group;

R ⁴Be not branching or branching C ₁-C ₆Alkyl;

N is 3-50.

2. as the desired purposes of claim 1, wherein multipolymer comprises 65-85mol% component (a) with copolymerized form, 10-25mol% component (b) and 5-15mol% component (c).

3. as claim 1 or 2 desired purposes, wherein multipolymer comprises 65-75mol% component (a) with copolymerized form, 15-25mol% component (b) and 5-10mol% component (c).

4. as claim 1 or 2 desired purposes, wherein multipolymer comprises the non-ionic monomer of formula I as component (c), wherein R with copolymerized form ¹Be methyl, R ²Be chemical bond, R ³Be C ₂-C ₃Alkylidene group, R ⁴Be C ₁-C ₂Alkyl and n are 5-40.

5. as claim 1 or 2 desired purposes, wherein multipolymer comprises the non-ionic monomer of formula I as component (c), wherein R with copolymerized form ¹Be methyl, R ²Be chemical bond, R ³Be ethylidene, R ⁴For methyl and n are 10-30.

6. as claim 1 or 2 desired purposes, wherein multipolymer contains-SO ₃ ^-Na ⁺And/or-SO ₄ ^-Na ⁺As end group.

7. as claim 1 or 2 desired purposes, wherein multipolymer is used as the deposition suppressant additive at the machine wash up in washing composition.